Context sensitive actor list retrieves temp folder data in blueprints while using source control

If a project uses source control and a blueprint has been diffed against previous revisions, the revisions will appear within the temp folder. This temp folders contents appear in context sensitive lists appropriate to the asset type. For instance, if using a "spawn actor from class" any actor blueprints within the temp folder will show up in the context sensitive list, duplicating any actors already within the editor.

1. Open any project connected to source control
2. Create a new blueprint (actor), name it "test"
3. Add several nodes to blueprint, including one "spawn actor from class" node.
4. Save blueprint and project.
5. Ensure new blueprint gets added to source control (in p4, use "mark for add" then "submit" changelist).
6. Re-open project
7. Re-open blueprint
8. Make changes to blueprint
9. Re-submit blueprint to perforce after compile/save.
10. In actor blueprint in editor, open file>diff>Revision1
11. In blueprint event graph, select spawn actor from class node and look for "test"

Results:

Two copies of test appear, one from it's contents location and one from the temp/diff folder.

Expected:

A single copy of test appears in the context sensitive menu.

Why am I getting a duplicate of a blueprint class in class selection drop down/list...?